Heart rate variability in adults with chronic musculoskeletal pain: A systematic review.

PURPOSE: The aim of this review was to compare the heart rate variability (HRV) responses at rest of adults with chronic musculoskeletal pain against healthy controls. METHODS: The PubMed, Scopus, Web of Science (Science and Social Science Citation Index), and CINAHL databases were searched, with no date restrictions. Two independent reviewers selected observational studies that characterized the HRV responses at rest in adults with chronic musculoskeletal pain compared with those of healthy controls. Methodological quality was assessed using the Downs and Black checklist. RESULTS: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. HRV in adults with chronic musculoskeletal pain was evaluated systematically. Of the 4893 studies screened, 20 of poor-to-moderate quality met the inclusion criteria. Most studies used electrocardiography and at least one time and/or frequency domain index. Studies were found that investigated HRV in adults with temporomandibular disorders, neck pain, whiplash, low back pain, and fibromyalgia. The heterogeneity of the studies in relation to painful conditions, parameters or position for HRV analysis precluded a meta-analysis. In general, these studies seem to show increased sympathetic and decreased parasympathetic modulation in adults with musculoskeletal pain when compared to controls. CONCLUSIONS: Adults with musculoskeletal pain exhibited a decline in HRV compared to controls. However, definitive conclusions cannot be drawn since the evidence is heterogeneous and of moderate quality. Further high-quality research with standardized measurements is needed.

Immediate Effects of the Combination of Interferential Therapy Parameters on Chronic Low Back Pain: A Randomized Controlled Trial.

OBJECTIVES: To compare the immediate analgesic effects of 2 kHz or 4 kHz interferential current (IFC) with different amplitude-modulated frequencies (AMFs) (2 Hz or 100 Hz) on chronic low back pain (CLBP). DESIGN: Three-arm double-blinded randomized controlled trial. SETTING: Primary care. PARTICIPANTS: 175 patients (19 to 60 years of age, 105 female) with CLBP. INTERVENTIONS: One session of IFC: Interferential group (GI): GI2 kHz/100 Hz, GI2 kHz/2 Hz, GI4  kHz/100 Hz, GI4 kHz/2 Hz, or placebo. MAIN OUTCOMES MEASURES: Pain intensity by numerical rating scale of pain (NRS), McGill Pain Questionnaire (MPQ), and algometry. RESULTS: There was a significant difference in NRS scores (P < 0.05) in the GI2 kHz/2 Hz, GI4 kHz/2 Hz, and GI4 kHz/100 Hz groups compared with those of the placebo group (PG), and a significant difference in MPQ scores in the GI4 kHz/2 Hz and GI4 kHz/100 Hz groups compared with those of the PG. In algometry, only the GI4 kHz/100 Hz group showed a significant difference (by 2 points in the lumbar region) compared with the PG. Of the carrier frequencies, an IFC of 4 kHz showed more effective results, although no significant difference was noted between the AMFs. CONCLUSION: An IFC with a carrier frequency of 4 kHz and an AMF of 100 Hz provide immediate analgesic effects in individuals with CLBP. CLINICAL TRIAL REGISTRATION NUMBER: RBR-59YGRB.

Effect of High- and Low-Frequency Transcutaneous Electrical Nerve Stimulation on Angiogenesis and Myofibroblast Proliferation in Acute Excisional Wounds in Rat Skin.

OBJECTIVE: This study evaluated the effects of high- (HF) and low-frequency (LF) transcutaneous electrical nerve stimulation on angiogenesis and myofibroblast proliferation in acute excisional wounds in rat skin. DESIGN: This was an experimental controlled and randomized study. PARTICIPANTS: An excisional wound was made on the back of 90 adult male EPM1-Wistar rats using an 8-mm punch. INTERVENTIONS: The animals were randomly assigned to the HF group (80 Hz), LF group (5 Hz), or control group. Transcutaneous electrical nerve stimulation (pulse duration, 200 microseconds; current amplitude, 15 mA) was delivered (session length, 60 minutes) on 3 consecutive days. MEAN OUTCOME MEASURE: Immunohistochemistry was performed on postoperative days 3, 7, and 14 for counting blood vessels and myofibroblasts. MEAN OUTCOME RESULTS: The LF group had significantly more blood vessels than the HF group on day 3 (P = .004). The HF group had significantly less blood vessels than did the control group on days 7 (P = .002) and 14 (P = .034) and less myofibroblasts than did both the LF and control groups on day 3 (P = .004) and less than did the control group on day 7 (P = .001). CONCLUSION: There seems to be a benefit to the use of LF transcutaneous electrical nerve stimulation in the healing of acute excisional wounds, but further studies are warranted.

Low-level laser therapy and light-emitting diode effects in the secretion of neuropeptides SP and CGRP in rat skin.

The phototherapy effects in the skin are related to biomodulation, usually to accelerate wound healing. However, there is no direct proof of the interrelation between the effects of low-level laser therapy (LLLT) and light-emitting diode (LED) in neuropeptide secretion, these substances being prematurely involved in the neurogenic inflammation phase of wound healing. This study therefore focused on investigating LLLT and LED in Calcitonin gene-related peptide (CGRP) and substance P (SP) secretion in healthy rat skin. Forty rats were randomly distributed into five groups with eight rats each: Control Group, Blue LED Group (470 nm, 350 mW power), Red LED Group (660 nm, 350 mW power), Red Laser Group (660 nm, 100 mW power), and Infrared Laser Group (808 nm, 100 mW power) (DMC® Equipamentos Ltda., São Carlos, São Paulo, Brazil). The skin of the animals in the experimental groups was irradiated using the punctual contact technique, with a total energy of 40 J, single dose, standardized at one point in the dorsal region. After 14 min of irradiation, the skin samples were collected for CGRP and SP quantification using western blot analysis. SP was released in Infrared Laser Group (p = 0.01); there was no difference in the CGRP secretion among groups. Infrared (808 nm) LLLT enhances neuropeptide SP secretion in healthy rat skin.

Anthropometry of the breast region: how to measure?

BACKGROUND: Breast region measurements are important for research, but they may also become significant in the legal field as a quantitative tool for preoperative and postoperative evaluation. Direct anthropometric measurements can be taken in clinical practice. The aim of this study was to compare direct breast anthropometric measurements taken with a tape measure and a compass. METHODS: Forty women, aged 18-60 years, were evaluated. They had 14 anatomical landmarks marked on the breast region and arms. The union of these points formed eight linear segments and one angle for each side of the body. The volunteers were evaluated by direct anthropometry in a standardized way, using a tape measure and a compass. RESULTS: Differences were found between the tape measure and the compass measurements for all segments analyzed (p>0.05). CONCLUSION: Measurements obtained by tape measure and compass are not identical. Therefore, once the measurement tool is chosen, it should be used for the pre- and postoperative measurements in a standardized way. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Effects of transcutaneous electrical nerve stimulation on pain, function, and descending inhibition in people with non-specific chronic low-back pain: a study protocol for a randomized crossover trial.

BACKGROUND: Low back pain (LBP) is a significant public health problem, is very prevalent, and is often characterized by the persistence of symptoms. Transcutaneous electrical nerve stimulation (TENS) may benefit people with chronic LBP because it can activate descending inhibitory pathways and inhibit central excitability. However, previous studies that have investigated the effects of TENS on pain in people with LBP have failed to use proper intensities of current, and the timing of the assessment of pain was not performed during the peak of the analgesic response or functional activities. Therefore, the present study aims to assess the effects of TENS on measures of pain, function, and descending inhibition using the maximal tolerable intensity of TENS in participants with LBP. METHODS/DESIGN: This study will be a randomized crossover trial. The participants for this study will be recruited from various places, including the University of Hartford, physical therapy clinics, and local businesses in the Hartford area, as well as online websites geared towards clinical trial recruitment. A total of 34 participants will receive all three treatments: active TENS, placebo TENS, and no treatment control. The treatment order will be randomized using a website-based randomization tool. For active TENS, a modulating frequency of 2-125 Hz will be applied with a variable pulse duration and maximal tolerable intensity for 30 min. The TENS will be left on for post-treatment testing to assess the effects during its maximally effective period for a total of 50 to 60 min. Furthermore, the intensity may be turned down if muscle twitching is present to ensure blinding of the evaluator. For placebo TENS, the unit will deliver current for 45 s, ramping to 0 in the last 15 s. The primary outcome will be pain intensity at rest and with movement, determined using the numerical pain rating scale. The secondary outcomes will be pressure pain threshold, heat pain threshold, temporal summation of pain, conditioned pain modulation, sit-to-stand test, and repeated trunk flexion. The assessments will be performed immediately before and after treatment. Statistical analysis of the data obtained will consider a significance level of p < 0.05. DISCUSSION: This study will provide evidence concerning the effects and mechanisms of TENS treatment in participants with chronic non-specific low back pain. The outcomes, including pain, function, and descending inhibition, will help us gain a greater understanding of how TENS can be used for these participants. TRIAL REGISTRATION: ClinicalTrials.gov NCT05812885. Registered on 24th May 2023.

Cardiac autonomic response to acute painful stimulus in individuals with chronic neck pain: A case-control study.

PURPOSE: Characterize heart rate and cardiac autonomic response to painful stimulus on neck pain. METHODS: Twenty-five individuals with neck pain and 25 healthy subjects were included. Heart rate variability and heart rate were assessed in the conditioned pain modulation test at pretest rest, during testing and in recovery. Heart rate variability indices were obtained using linear and nonlinear methods. RESULTS: No significant differences were observed between groups regarding heart rate and the linear methods (p > 0.05). However, significant difference was observed between groups regarding nonlinear methods (standard deviation of the instantaneous variability of beat-to-beat interval variability, p = 0.005) CONCLUSIONS: Individuals with chronic neck pain showed autonomic responses similar to those of their healthy counterparts during the conditioning stimulus.

The combined effect of transcutaneous electrical nerve stimulation and transcutaneous auricular vagus nerve stimulation on pressure and heat pain thresholds in pain-free subjects: a randomized cross-over trial.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a non-invasive modality that utilizes electrical currents to modulate pain in populations with acute and chronic pain. TENS has been demonstrated to produce hypoalgesic effects in postoperative pain, fibromyalgia, knee osteoarthritis, and healthy subjects. Transcutaneous auricular vagus nerve stimulation (TaVNS) is a non-invasive modality that modulates the vagus nerve by stimulating its auricular branches. The effects of the combination of TENS and TaVNS on producing an analgesic response have not been studied. Considering that TENS and TaVNS both stimulate similar analgesic pathways but through different means of activation, we can hypothesize that a combination of both methods can produce a more pronounced analgesic response. Therefore, the objective of this study is to assess the hypoalgesic effect of a combination of TENS and TaVNS in pain-free subjects. METHODS/DESIGN: The study will be a simple crossover design conducted at the University of Hartford. Subjects will be recruited from the University of Hartford population via oral communication, digital flyers, and posters on campus. Thirty participants will undergo two sessions in a crossover manner with one week in between. During one session, the participants will receive TENS with active TaVNS and the other session will be a placebo procedure (TENS with placebo TaVNS). The order of these sessions will be randomized. Importantly, the pressure pain threshold (PPT) and heat pain threshold (HPT) assessors will be blinded to the treatment category. For active TaVNS, a frequency of 25 Hz will be applied with a pulse duration of 200 µs. For placebo TaVNS, the intensity will be increased to a sensory level and then decreased to 0 mA. High-frequency TENS of 100 Hz will be applied in both sessions, with a pulse duration of 200 µsec, asymmetrical biphasic square waveform, and intensity of maximal tolerance without pain. TENS and TaVNS will be turned on for 30 min after a baseline measurement of outcomes. TENS and TaVNS will then be turned off, but the electrodes will remain on until completion of post-treatment assessment. Pressure pain threshold, heat pain threshold, blood pressure, oxygen saturation, and heart rate will be tested 4 times: Once pre-intervention, once during intervention, once immediately after the intervention, and once 15 min post-intervention. Statistical analysis of the data obtained will consider a significance level of p < 0.05. DISCUSSION: This study will provide evidence concerning the combined effects of TENS and TaVNS on pain threshold in pain-free participants. Based on the outcomes, a greater understanding of how TENS and TaVNS, when used in conjunction, can modulate pain pathways. TRIAL REGISTRATION: ClinicalTrials.gov NCT06361381. Registered on 09 April 2024.

Does manual therapy meaningfully change quantitative sensory testing and patient reported outcome measures in patients with musculoskeletal impairments related to the spine?: A 'trustworthy' systematic review and meta-analysis.

OBJECTIVES: To perform a 'trustworthy' systematic review (SR) with meta-analysis on the potential mechanisms of manual therapy used to treat spinal impairments. DESIGN: SR with meta-analysis. LITERATURE SEARCH: Articles published between January 2010 and October 2022 from CENTRAL, CINAHL, MEDLINE, PubMed, ProQuest, and PEDro. METHODS: This SR included English-language randomized clinical trials (RCTs) involving manual therapy to treat spinal impairments in adults. The primary outcome was pressure pain thresholds (PPTs). To synthesize RCTs with high confidence in estimated effects using the GRADE, RCTs with questionable prospective, external, and internal validity, and high risk of bias (RoB) were excluded. RESULTS: Following title and abstract screening, 89 full-text RCTs were reviewed. Twenty-two studies included the criteria of interest. Sixteen were not prospectively registered, two contained discussion/conclusions judged to be inconsistent with the registry, and one was rated as having a high RoB. Three studies met the inclusion criteria; heterogeneous interventions and locations for PPT testing prevented synthesis into practice recommendations. The two studies with high confidence in estimated effects had small effect sizes, and one study had confidence intervals that crossed zero for the outcome measures of interest. DISCUSSION: Standardized PPT testing, as a potential measure of centrally mediated pain, could provide clues regarding the mechanisms of manual therapy or help identify/refine research questions. CONCLUSION: High-quality RCTs could not be synthesized into strong conclusions secondary to the dissimilarity in research designs. Future research regarding quantitative sensory testing should develop RCTs with high confidence in estimated effects that can be translated into strong recommendations.

Effectiveness of interferential current in patients with chronic non-specific low back pain: a systematic review with meta-analysis.

BACKGROUND: There is no systematic review assessing the effectiveness of interferential current (IC) in patients with low back pain. OBJECTIVE: To investigate the effectiveness of IC in patients with chronic non-specific low back pain. METHODS: The databases PUBMED, EMBASE, PEDro, Cochrane Library, CINAHL, and SCIELO were searched. Randomized controlled trials reporting pain intensity and disability in patients with chronic non-specific low back pain, in which IC was applied were included. Methodological quality was assessed using the PEDro scale. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to evaluate the quality of evidence. RESULTS: Thirteen RCTs were considered eligible for this systematic review (pooled n = 1367). Main results showed moderate-quality evidence and moderate effect sizes that IC probably reduces pain intensity and disability compared to placebo immediately post-treatment (Pain: MD = -1.57 points; 95% CI -2.17, -0.98; Disability: MD = -1.51 points; 95% CI -2.57, -0.46), but not at intermediate-term follow-up. Low-quality evidence with small effect size showed that IC may reduce pain intensity (SMD = -0.32; 95% CI -0.61, -0.03, p = 0.03) compared to TENS immediately post-treatment, but not for disability. There is very low-quality evidence that IC combined with other interventions (massage or exercises) may not further reduce pain intensity and disability compared to the other interventions provided in isolation immediately post-treatment. CONCLUSION: Moderate-quality evidence shows that IC is probably better than placebo for reducing pain intensity and disability immediately post-treatment in patients with chronic non-specific low back pain.

Low-level laser irradiation, cyclooxygenase-2 (COX-2) expression and necrosis of random skin flaps in rats.

Skin flaps are still a matter of concern among surgeons, as failures can occur leading to flap necrosis. However, low-level laser irradiation has been reported as an effective tool to improve the viability of ischemic flaps, yet its mechanisms of action remain unclear. We investigated the effect of low-level laser irradiation on the viability of random skin flaps in rats and determined COX-2 expression in the flap pedicle. The study animals comprised 24 EPM-1 Wistar rats which were randomly allocated into three equal groups. A cranially based dorsal random skin flap measuring 10 × 4 cm was created in all the animals. In one group, laser irradiation was simulated (sham group), and in the other two groups the animals were irradiated at 12 points with 0.29 J at 20 mW (energy density 10.36 J/cm(2), irradiance 0.71 W/cm(2)), or with 7.3 J at 100 mW (energy density 260.7 J/cm(2), irradiance 3.57 W/cm(2)). These procedures were applied to the cranial half of the flap immediately after surgery and were repeated on days 2 and 5 after surgery. The percentage necrotic area was determined on day 7 after surgery by the paper template method. The immunohistochemical expression of COX-2 in the samples was given scores from 0 to 3. The necrotic area was smaller in group irradiated at 7.3 J compared to sham-treated group and to the group irradiated at 0.29 J (P < 0.05); there was no difference between the sham-treated group and group irradiated at 0.29 J. COX-2 expression was lower in the group irradiated at 7.3 J than in the sham-treated group and the group irradiated at 0.29 J (P < 0.001). Low-level laser therapy was effective in decreasing random skin flap necrosis in rats using a laser energy of 7.30 J per point. Laser irradiation also decreased the expression of COX-2 in the flap pedicle.

GaAs 904-nm laser irradiation improves myofiber mass recovery during regeneration of skeletal muscle previously damaged by crotoxin.

This work investigated the effect of gallium arsenide (GaAs) irradiation (power: 5 mW; intensity: 77.14 mW/cm(2), spot: 0.07 cm(2)) on regenerating skeletal muscles damaged by crotoxin (CTX). Male C57Bl6 mice were divided into six groups (n = 5 each): control, treated only with laser at doses of 1.5 J or 3 J, CTX-injured and, CTX-injured and treated with laser at doses of 1.5 J or 3 J. The injured groups received a CTX injection into the tibialis anterior (TA) muscle. After 3 days, TA muscles were submitted to GaAs irradiation at doses of 1.5 or 3 J (once a day, during 5 days) and were killed on the eighth day. Muscle histological sections were stained with hematoxylin and eosin (H&E) in order to determine the myofiber cross-sectional area (CSA), the previously injured muscle area (PIMA) and the area density of connective tissue. The gene expression of MyoD and myogenin was detected by real-time PCR. GaAs laser at a dose of 3 J, but not 1.5 J, significantly increased the CSA of regenerating myofibers and reduced the PIMA and the area density of intramuscular connective tissue of CTX-injured muscles. MyoD gene expression increased in the injured group treated with GaAs laser at a dose of 1.5 J. The CTX-injured, 3-J GaAs laser-treated, and the CTX-injured and treated with 3-J laser groups showed an increase in myogenin gene expression when compared to the control group. Our results suggest that GaAs laser treatment at a dose of 3 J improves skeletal muscle regeneration by accelerating the recovery of myofiber mass.

Features and methods to discriminate between mechanism-based categories of pain experienced in the musculoskeletal system: a Delphi expert consensus study.

ABSTRACT: Classification of musculoskeletal pain based on underlying pain mechanisms (nociceptive, neuropathic, and nociplastic pain) is challenging. In the absence of a gold standard, verification of features that could aid in discrimination between these mechanisms in clinical practice and research depends on expert consensus. This Delphi expert consensus study aimed to: (1) identify features and assessment findings that are unique to a pain mechanism category or shared between no more than 2 categories and (2) develop a ranked list of candidate features that could potentially discriminate between pain mechanisms. A group of international experts were recruited based on their expertise in the field of pain. The Delphi process involved 2 rounds: round 1 assessed expert opinion on features that are unique to a pain mechanism category or shared between 2 (based on a 40% agreement threshold); and round 2 reviewed features that failed to reach consensus, evaluated additional features, and considered wording changes. Forty-nine international experts representing a wide range of disciplines participated. Consensus was reached for 196 of 292 features presented to the panel (clinical examination-134 features, quantitative sensory testing-34, imaging and diagnostic testing-14, and pain-type questionnaires-14). From the 196 features, consensus was reached for 76 features as unique to nociceptive (17), neuropathic (37), or nociplastic (22) pain mechanisms and 120 features as shared between pairs of pain mechanism categories (78 for neuropathic and nociplastic pain). This consensus study generated a list of potential candidate features that are likely to aid in discrimination between types of musculoskeletal pain.

Does preoperative electrical stimulation of the skin alter the healing process?

BACKGROUND: In vitro studies have demonstrated that electrical current may affect fibroblast proliferation and synthesis of collagen fibers. In humans, the application of electrical current by positioning the positive electrode on skin wounds resulted in thinner hypertrophic scars. The aim of this study was to evaluate the effects of preoperative electrical stimulation on cutaneous wound healing in rats. MATERIALS AND METHODS: Forty rats were divided into two groups of 20 animals each. In the control group, an incision was made on the back of the animals. In the stimulation group, a preoperative electrical stimulation was applied using a rectangular pulse current at a frequency of 7.7 Hz, and intensity of 8 mA, for 30 min, with the positive electrode placed on the back of the animal, and the negative electrode placed on the abdominal wall. Following, an incision was made on their back. Biopsy was carried out on postoperative day 7 and 14, and histologic analysis was performed. RESULTS: The number of newly formed vessels, fibroblasts, and type III collagen fibers in the stimulation group on postoperative day 7 were greater than those in the control group. CONCLUSIONS: Preoperative positive-polarity electrical stimulation positively affects angiogenesis and fibroblast proliferation.

Effects of neuromuscular electrical stimulation on torque and performance in recreational distance runners: A randomized controlled trial.

INTRODUCTION: Neuromuscular electrical stimulation (NMES) is used by athletes to improve muscle performance. However, evidence on the use of NMES in long distance runners is scarce. As such, this study aimed to evaluate the effects of NMES on the muscle torque and sports performance of long-distance recreational runners. METHODS: This was a blinded randomized controlled trial. Data from 30 volunteers were analyzed. Participants were randomly allocated to an experimental (n = 15) or control group (n = 15). The experimental group was submitted to running training (RT) and a strengthening protocol with NMES (1 kHz, modulated in 2 ms bursts, 50 Hz modulated burst frequency and 10% duty cycle, 15 min totaling 18 contractions per sessions) for 6 weeks, with 3 sessions per week, while controls were submitted to RT alone. The following variables were analyzed: peak isometric (ISO), concentric (CON), and eccentric (ECC) torque of the quadriceps muscle in voluntary contractions, ventilatory anaerobic thresholds (VATs), maximal oxygen uptake (VO2max), and oxygen cost of transport (OCT). RESULTS: The NMES group obtained higher values of ISO, 21.04% (p = 0.001), CON, 21.97% (p = 0.001) and ECC, 18.74% (p = 0.001) peak torque and VAT1, 9.56% (p = 0.001), as well as a statistically significant improvement in oxygen cost of transport at VAT1 when compared to controls (p = 0.001). CONCLUSION: NMES was effective in improving peak isometric, concentric and eccentric quadriceps muscle torque, in addition to being an interesting resource for enhancing sports performance in long-distance recreational runners and future clinical trials should be performed to compare the use of NMES to different forms of training over longer training periods.

Biopsychosocial Aspects in Individuals with Acute and Chronic Rotator Cuff Related Shoulder Pain: Classification Based on a Decision Tree Analysis.

Biopsychosocial aspects seem to influence the clinical condition of rotator cuff related shoulder pain (RCRSP). However, traditional bivariate and linear analyses may not be sufficiently robust to capture the complex relationships among these aspects. This study determined which biopsychosocial aspects would better classify individuals with acute and chronic RCRSP and described how these aspects interact to create biopsychosocial phenotypes in individuals with acute and chronic RCRSP. Individuals with acute (

Effects of transcutaneous electrical nerve stimulation on pain intensity during application of carboxytherapy in patients with cellulite: A randomized placebo-controlled trial.

BACKGROUND: Carboxytherapy may generate local pain that is considered the main limiting factor in clinical practice. Transcutaneous electric nerve stimulation (TENS) is widely used in the control of acute pain; however, the effect of TENS on pain relief during carboxytherapy has not been studied to date. AIMS: To assess the effect of TENS on pain intensity during carboxytherapy in patients with cellulite in the gluteal region. PATIENTS/METHODS: This randomized clinical trial was conducted with 84 patients, 18-44 years of age, who had moderate cellulite in the gluteal region, according to Cellulite Severity Scale, but never received carboxytherapy. Patients were randomized into 3 groups: active TENS, placebo TENS, and control group. For the intervention, skin depressions with cellulite were outlined, and the gluteal area to be treated was defined. The subcutaneous injection of CO2 was performed using 0.30 × 13 mm-needles at a 45° angle, with a controlled flow rate of 100 mL/min maintained for 1 minute at each puncture site. The parameters for TENS were as follows: frequency of 100 Hz and pulse duration of 200 µs; TENS intensity was adjusted until the patient reported strong paresthesia. The visual numeric pain rating scale was used to assess pain intensity after each puncture. RESULTS: The active TENS group reported lower pain intensity compared to the placebo TENS (P < .0001) and control (P < .0001) groups. CONCLUSIONS: Transcutaneous electric nerve stimulation (TENS) was effective in reducing pain intensity during carboxytherapy in patients with cellulite in the gluteal region.

Low-level laser therapy and interferential current in patients with knee osteoarthritis: a randomized controlled trial protocol.

The aim of this study is to investigate the effects of low-level laser therapy and interferential current (IFC) on pain intensity, central sensitization, muscle strength and functional capacity in patients with knee osteoarthritis. Participants will be patients aged between 50 and 80 years, with knee osteoarthritis, pain intensity ranging from 3 to 8 points (0-10 scale), Lequesne Algofunctional Index ranging from 5 to 15 points, and Kellgren & Lawrence grade ≥2. A total of 168 patients will be randomly allocated into four groups as follows: active IFC + laser sham (G1), IFC sham + active laser (G2), active IFC + laser (G3) and IFC + laser sham (G4). Evaluators will be blinded to group allocation. Primary outcomes will be pain at rest and during movement measured with the visual analog pain scale. Clinical Trials Registry (NCT02898025. Registered on 20 April 2016).

Does the use of interferential current prior to pilates exercises accelerate improvement of chronic nonspecific low back pain?

AIM: To evaluate whether active interferential current (AIC) before pilates exercises improves pain faster than placebo interferential current (PIC) in patients with chronic nonspecific low back pain (CNLBP). METHODS: A total of 142 patients with CNLBP were treated with AIC or PIC before pilates exercises. Pain intensity was measured daily before and after treatment by Pain Numerical Rating Scale. Statistical analysis was performed using survival analysis for Kaplan-Meier method. RESULTS: The AIC group presented 30% reduction of pain one session, 50% reduction of pain two sessions and 100% reduction of pain three sessions faster than the PIC group and these improvements were statistically significant (p < 0.05). CONCLUSION: The AIC before pilates exercises can reduce pain faster than PIC in patients with CNLBP.

High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture.

OBJECTIVE: To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. METHOD: Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. RESULTS: No significant difference was observed among the groups regarding collagen realignment (types I or III collagen) or quantity of blood vessels. CONCLUSION: High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.